CN1954998B - Liquid ejection apparatus, recording apparatus, and field generating unit - Google Patents

Abstract

The present invention proposes a liquid ejection apparatus including a liquid ejection head that has a nozzle plate and ejects liquid from an orifice of the nozzle plate toward a recording material while reciprocating over the recording material, and a platen that supports the recording material from a back surface of the recording material to position the recording material at a position facing the nozzle plate in a direction in which the liquid is ejected. The liquid ejection apparatus further includes: a first electrode provided on the platen side between the liquid ejection head and the platen; a second electrode provided on the liquid ejection head side between the liquid ejection head and the platen; and a potential difference generating portion having one end connected to the first electrode and the other end connected to the second electrode, and generating a potential difference between the second electrode and the first electrode.

Description

Liquid ejection device, recording device and field generating unit

Cross References to Related Applications

This patent application claims priority from Japanese Patent Applications No. 2005-311950 and No. 311951 filed in Japan on October 26, 2005, the contents of which are incorporated herein by reference.

technical field

The present invention relates to a liquid ejection device, a recording device, and a field generating unit. More particularly, the present invention relates to a liquid ejection apparatus and a recording apparatus for attaching liquid discharged from holes of a nozzle plate mounted on a liquid ejection head to a recording material, and a field generating unit usable in these apparatuses.

Background technique

In liquid ejection apparatuses, liquid droplets discharged from holes of a nozzle plate in current liquid ejection apparatuses are miniaturized to about several pl or picoliters (picoliters) according to the need for improvement in the definition of recorded images. Because such tiny droplets have an extremely small mass, once they are expelled, they quickly lose their kinetic energy due to the viscous resistance of the air. Specifically, for example, when a droplet of less than 3 pl flies a distance of about 3 mm in the air, the velocity of the droplet becomes substantially zero. Since the falling motion by the acceleration of gravity and the viscous resistance of the air are almost balanced in the minute liquid droplet that has lost kinetic energy, it takes a long time for the minute liquid droplet to fall completely.

Furthermore, in order to impart greater kinetic energy to the liquid droplets, it is also possible to increase the ejection speed of the liquid ejected from the liquid ejection head. However, when the ejection velocity from the nozzle plate is actually increased, extremely fine droplets called ink mist tend to be generated when the droplets leave the nozzle plate. Also, since the viscous resistance of the air acting on each droplet becomes still larger, it was found that the travel distance of the droplet was shortened instead of the travel distance of the droplet before the ejection velocity was increased.

Floating liquid droplets generated as a result of the various phenomena described above are called aerosols, and float in the vicinity of the travel area of the liquid ejection head. A part of the aerosol floats to the outside of the liquid ejecting device and thus adheres near the liquid ejecting device to detract from the appearance of the device. Also, most of the aerosols adhere to every part inside the liquid ejecting apparatus after a while. In particular, when aerosols adhere to a conveyance path of a recording material such as a platen, the recording material that is conveyed next becomes soiled. Also, when aerosols adhere to electrical circuits, rotary scales, linear scales, or various types of optical sensors of liquid ejection equipment, this can cause malfunction of the equipment. Also, when the user touches the portion to which the aerosol adheres, the user's hands are soiled.

The liquid ejection apparatus described in the following Japanese Patent Application Laid-Open No. 2005-186290 forms an electric field between a nozzle plate and a substance to be processed so that Coulomb force toward the substance acts on the liquid droplets. In this way, it is described that the droplets are positively reached to the substance to prevent the generation of aerosols. Also, Japanese Patent Application Laid-Open No. 2005-186290 suggests that electrification of a substance to be processed caused by attaching a charged liquid to the substance is prevented by changing the polarity of a voltage to be applied to the substance.

However, the configuration disclosed in Japanese Patent Application Laid-Open No. 2005-186290, in addition to voltage applying means for applying a voltage to a substance to be processed, includes, as essential components, switching means for changing the polarity of the applied voltage, Controls for measuring transition times, etc. Therefore, the size and manufacturing cost of the liquid ejection apparatus must be increased in order to realize the configuration as described in Japanese Patent Application Laid-Open No. 2005-186290.

Contents of the invention

Accordingly, it is an object of some aspects of the present invention to propose a liquid ejection device, a recording device, and a field generating unit capable of solving the above-mentioned problems. The above and other objects can be achieved by the combinations described in the independent claims. The dependent claims define further advantageous and exemplary combinations of the invention.

In order to solve this problem, according to a first aspect of the present invention, a liquid ejection device is proposed, comprising a liquid ejection head and a platen (or a paper platen, a recording material member), the liquid ejection head has a nozzle plate and injects the liquid The platen is ejected toward the recording material from the hole of the nozzle plate while reciprocating above the recording material, and the platen supports the recording material from the back side of the recording material to position the recording material facing the nozzle plate in the direction in which the liquid is ejected. The liquid ejecting apparatus includes: a first electrode disposed on the platen side between the liquid ejecting head and the platen; a second electrode disposed between the liquid ejecting head and the platen on the liquid ejecting side. the head side; and a potential difference generating part, one end of which is connected to the first electrode and the other end is connected to the second electrode, and the potential difference generating (generating) part is connected between the second electrode and the first electrode generates a potential difference between the two electrodes, wherein the potential difference generating section adjusts the output so that the potential difference becomes an original value when the potential difference between the second electrode and the first electrode is changed, and keeps constant The potential difference between the second electrode and the first electrode.

The second electrode may be a conductive nozzle plate, and the first electrode is electrically connected to the recording material supported on the platen. Also the liquid ejection device may generate an electric field between the nozzle plate and the recording material on the platen to electrically attract the liquid ejected from the holes of the nozzle plate toward the recording material. In this way, an electric field is formed between the nozzle plate and the recording material. Thus, since the ejected liquid droplets must reach the recording material, generation of suspended particles (or aerosol) is prevented. Also, the potential difference between the nozzle plate generating this electric field and the recording material is constantly maintained by the potential difference generating portion. Therefore, since the electric field is constantly maintained, even if the charged liquid adheres to the recording material, it is not necessary to provide switching means for applied voltage or control means for controlling the switching time.

Also, in the liquid ejecting apparatus, the first electrode may be mounted on the platen and electrically connected to the recording material supported on the platen.

Also, in the liquid ejecting apparatus, the first electrode may include a conductive member mounted on a portion of the platen that is immediately adjacent to (or adjacent to, against) the back surface of the recording material. In this way, since the first electrode contacts the recording material immediately under the nozzle plate to control the potential, the potential of the recording material can be effectively controlled.

Also, in the liquid ejection device, the first electrode may include a conductive member installed through the platen in a direction in which the liquid is ejected, and one end of the first electrode may be in contact with the recording material, and The other end may be electrically connected to the potential difference generating portion. In this way, wiring for connecting the first electrode to the potential difference generating portion can be performed on the back side of the press plate. Therefore, wiring in the liquid ejecting device becomes easy.

Also, in the liquid ejecting apparatus, the first electrode may include a conductive member that is aligned with the platen on at least one side just (just) before and just after the platen on the conveyance path of the recording material. access to the recording material described above. In this way, an arbitrary position and an arbitrary material can be selected to form the first electrode.

Also, the liquid ejecting apparatus may further include: a conveyance section including a conveyance (or conveyor) driving roller that is rotationally driven and a conveyance (or conveyor) driven roller that follows the rotation of the conveying driving roller rotates while pressing the recording material on the conveying driving roller, and the conveying portion feeds the recording material onto the platen; and a discharge portion including a rotationally driven a discharge driving roller, and a discharge driven roller which rotates with the rotation of the discharge driving roller and simultaneously presses the recording material against the discharge driving roller, and which discharges the recording material from the platen At least one of the conveying drive roller, conveying driven roller, discharge driving roller and discharge driven roller is a conductive roller formed of a conductive material; and the conductive roller is electrically connected to the recording material as a first electrode. In this way, the electric field is formed between the nozzle plate and the recording material. Thus, since the ejected liquid droplets must reach the recording material, the generation of aerosols is prevented. Also, the potential difference between the nozzle plate and the recording material generating this electric field is constantly maintained by the potential difference generating portion. Therefore, since the electric field is constantly maintained, even if the charged liquid adheres to the recording material, it is not necessary to set the switching of the applied voltage

(or switching) device or control device for controlling the switching (or switching) time.

Also, in the liquid ejecting apparatus, the conveying driving roller and the discharging driving roller may be conductive rollers. In this way, since the recording material is connected (or coupled) to the potential difference generating portion just before the pressing plate and after the pressing plate, the potential of the recording material on the pressing plate is stabilized.

Also, in the liquid ejection apparatus, the conveyance driven roller and the discharge driven roller may be conductive rollers. In this way, the liquid ejection device can control the potential of the recording material through existing elements. In this way, since the recording material is connected to the potential difference generating portion just before the pressing plate and just after the pressing plate, the potential of the recording material on the pressing plate is stabilized. Also, since the conveyance driven roller and the discharge driven roller have a simple supporting structure, electrical connection to the potential difference generating portion is easy.

Also, in the liquid ejecting apparatus, all of the conveyance drive roller, conveyance driven roller, discharge drive roller, and discharge driven roller may be conductive rollers. In this way, the potential of the recording material passing through the platen can be reliably controlled.

Also, according to a second aspect of the present invention, there is proposed a field generating (generating) unit mounted on a liquid ejecting apparatus including a liquid ejecting head having a nozzle plate and a platen. The liquid is ejected from the holes of the nozzle plate toward the recording material while reciprocating over the recording material, and the platen supports the recording material from the back of the recording material to position the recording material facing the nozzle plate in the direction in which the liquid is ejected. The field generating unit includes: a first electrode provided between the liquid ejection head and the platen on the side of the platen; a second electrode provided between the liquid ejection head and the platen on the side of the liquid ejection the head side; and a potential difference generating part, one end of which is connected to the first electrode and the other end is connected to the second electrode, and the potential difference generating part is between the second electrode and the first electrode There is a potential difference between them. In this way, the above-mentioned aerosol generation prevention function can be added to an existing liquid ejection device that does not initially have such a function, wherein the potential difference generating portion is the potential between the second electrode and the first electrode. The output is adjusted so that the potential difference becomes an original value when the difference is changed, and the potential difference between the second electrode and the first electrode is kept constant.

The second electrode may be a conductive nozzle plate, the first electrode may be electrically connected to the recording material supported on the platen, and the field generating unit may generate an electric field between the nozzle plate and the recording material on the platen. The liquid ejected from the holes of the nozzle plate toward the recording material is electrically attracted. In this way, the generation prevention function of aerosols described above can be added to existing liquid ejection apparatuses that do not originally have such a function.

Also, in the liquid ejection apparatus on which the field generating unit is mounted, the first electrode may be mounted on the platen and electrically connected to the recording material supported on the platen.

The liquid ejecting apparatus on which the field generating unit is mounted may further include: a conveyance part including a conveyance driving roller driven in rotation, and a conveyance driven roller following rotation of the conveyance driving roller while rotating and pressing the recording material on the conveyance drive roller, and the conveyance part feeds the recording material to the platen; and a discharge part comprising a discharge drive roller driven rotationally, and a discharge driven roller that rotates with the rotation of a discharge drive roller while pressing the recording material against the discharge drive roller, and the discharge section sends the recording material from the top of the platen, conveying At least one of the driving roller, the transport driven roller, the discharge driving roller, and the discharge driven roller is a conductive roller formed of a conductive material; and the conductive roller is electrically connected to the recording material as a first electrode. In this way, the contamination prevention function for the above-mentioned aerosols can be added to existing liquid ejection apparatuses that do not originally have such a function.

Furthermore, according to a third aspect of the present invention, there is proposed a recording apparatus including a recording head and a platen, the liquid ejection head having a nozzle plate and discharging ink from holes of the nozzle plate toward a recording material while above the recording material Reciprocating, the platen supports the recording material from the back of the recording material to position the recording material at a position facing the nozzle plate in the direction in which the ink is discharged. The recording apparatus includes: a first electrode provided on the platen side between the recording head and the platen; a second electrode provided on the recording head side between the recording head and the platen; and a potential difference generating section, one end of which is connected to the first electrode and the other end is connected to the second electrode, and the potential difference generating section generates a potential difference between the second electrode and the first electrode , wherein the potential difference generating section adjusts the output so that the potential difference becomes an original value when the potential difference between the second electrode and the first electrode is changed, and is constantly maintained at the second The potential difference between the electrode and the first electrode. In this way, the recording apparatus can prevent the generation of aerosols.

Also, the second electrode may be a conductive nozzle plate, the first electrode may be electrically connected to the recording material supported on the platen, and the recording apparatus may generate an electric field between the nozzle plate and the recording material on the platen The ink ejected from the holes of the nozzle plate toward the recording material is electrically attracted.

Also, in the recording apparatus, the first electrode may be mounted on the platen and electrically connected to the recording material supported on the platen.

And the recording apparatus may further include: a conveying section including a conveying driving roller that is rotationally driven, and a conveying driven roller that rotates with the rotation of the conveying driving roller and simultaneously the recording material is pressed against the conveying driving roller, and the conveying part sends the recording material to the platen; and the discharging part includes a discharging driving roller driven in rotation, and a discharging driven roller, the The discharge driven roller rotates with the rotation of the discharge drive roller and simultaneously presses the recording material against the discharge drive roller, and the discharge part sends the recording material from the top of the platen, the conveyance drive roller, the conveyance driven roller At least one of the roller, the discharge driving roller, and the discharge driven roller is a conductive roller formed of a conductive material; and the conductive roller is electrically connected to the recording material as a first electrode. In this way, the recording apparatus can prevent the generation of aerosols.

This summary of the invention does not necessarily describe all essential features of the invention. The invention may also be a partial combination of the features described above.

Description of drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following description of presently preferred exemplary embodiments, taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a perspective view overviewing the entirety of an inkjet type recording apparatus;

FIG. 2 is a perspective view showing the internal mechanism of the inkjet type recording apparatus;

3 is a sectional view showing an aerosol generation prevention mechanism according to an embodiment;

Fig. 4 is a schematic diagram explaining the operation of the aerosol generation prevention mechanism;

5 is a sectional view showing the structure of an aerosol generation preventing mechanism according to another embodiment;

Fig. 6 is a sectional view showing the structure of another aerosol generation prevention mechanism;

Fig. 7 is a sectional view showing the structure of a further additional aerosol generation prevention mechanism;

Fig. 8 is a sectional view showing the structure of a further additional aerosol generation prevention mechanism;

Fig. 9 is a schematic diagram for explaining the operation of the aerosol generation prevention mechanism;

10 is a sectional view showing the structure of an aerosol generation preventing mechanism according to another embodiment; and

Fig. 11 is a sectional view showing the structure of another aerosol generation prevention mechanism.

Detailed ways

Embodiments of the invention will now be described on the basis of preferred embodiments which are not intended to limit the scope of protection of the invention but merely illustrate the invention. All of the features described in the embodiments and combinations of features are not necessarily essential to the present invention.

FIG. 1 is a perspective view overviewing an inkjet type recording apparatus 10 as an example of an embodiment of the present invention, and FIG. 1 shows a state where a top case 110 as a cover is opened. As shown in this figure, the inkjet type recording apparatus 10 includes a bottom case 120 as a base of the device, a top case 110 forming a housing together with the bottom case 120, a paper support 130 attached to the rear of the bottom case 120, and A discharge (or paper discharge) tray 140 is formed in front of the bottom case 120 . Moreover, the inkjet type recording apparatus 10 includes a platen (or platen part, recording material part) 150 horizontally arranged in the bottom case 120, and a carriage (or carriage) arranged on the upper side of the platen 150 and inside the casing. )160.

In the inkjet type recording apparatus 10 as described above, the recording paper 170 accommodated on the paper support 130 is sent inside one by one by a supply (or paper feeding) section not shown, and then passed A conveying (or paper feeding) portion not shown is sent to the platen 150 . Also, the recording paper is delivered to a discharge tray 140 through a discharge portion not shown. Also, in each of the supply section, conveyance section, and discharge section, the recording paper 170 is supplied, conveyed, and discharged while the paper is held between a drive roller that is rotationally driven and a slave that rotates with the drive roller. between the moving rollers.

Also, in the inkjet type recording apparatus 10 , the carriage 160 reciprocates on the upper side of the platen 150 in a direction perpendicular to the conveying direction of the recording paper 170 . Therefore, since the conveyance of the recording paper 170 and the reciprocating motion of the carriage 160 are alternately performed, the entire top surface of the recording paper 170 can be scanned by the carriage 160 so that the carriage 160 can perform a recording operation on an arbitrary area on the recording paper 170 .

FIG. 2 shows a perspective view of an internal mechanism 20 of the inkjet recording apparatus 10 shown in FIG. 1 in a state where a frame 210 including side portions 212 and 214 is pulled out. As shown in this figure, the internal mechanism 20 is mainly formed inside an area bounded by a frame 210 arranged rearwardly and generally vertically and the pair of side portions 212 and 214 and the pair of side portions 212 and 214. 212 and 214 extend from both ends of the frame 210 to the front in parallel to each other.

As shown in this figure, in the internal mechanism 20, the carriage 160 is supported by a guide shaft 220 passing therethrough. Both ends of the guide shaft 220 are supported by the side parts 212 and 214 , and the guide shaft 220 is horizontally arranged in parallel with the frame 210 . Accordingly, the carriage 160 can move horizontally along the guide shaft 220 .

Behind the carriage 160 , a pair of pulleys 232 and 234 and a timing belt (cog belt) 230 tied to the pulleys 232 and 234 are arranged in front of the frame 210 . A pulley 234 is rotationally driven by a carriage motor 236 . Also, a timing belt 230 is connected to the rear of the carrier 160 . Accordingly, the carriage 160 can reciprocate according to the operation of the carriage motor 236 .

Also, the carriage 160 is loaded with the ink cartridge 162 from the upper side, and at the same time includes the recording head 164 at the lower part. The recording head 164 includes a nozzle plate 166 made of metal that includes holes for discharging ink on an upper surface. Accordingly, ink is discharged toward the lower side from the carriage 160 . Also, the carrier 160 is connected with the electronic circuit 250 at the rear of the frame 210 through a ribbon-shaped multi-core cable 240 . Since the multi-core cable 240 is flexibly bent according to the movement of the carrier 160 , the multi-core cable 240 does not interfere with the reciprocating motion of the carrier 160 .

The platen 150 is disposed on a lower side of a region along which the carriage 160 reciprocates. The platen 150 supports the recording paper 170 passing along the bottom of the carriage 160 from the lower side so that the distance between the nozzle plate 166 and the recording paper 170 is kept constant. Also, a recess 152 is formed on the top surface of the pressing plate 150 , and the absorbing member 260 is accommodated in the recess 152 . The absorbing member 260 receives ink discharged from the recording head 164 toward a region where the recording paper 170 does not exist.

In addition, ink adheres to the absorbing member 260 as the operation time of the inkjet type recording apparatus 10 elapses. When the recording paper 170 comes into contact with the absorbing member 260 to which the ink adheres, the back of the recording paper 170 is stained with ink. Thus, since the rib portion is formed on the top surface of the platen 150 to lift and support the recording paper 170 from the lower side, the space between the platen 150 and the recording paper 170 is maintained to prevent them from contacting each other. Specifically, a gap of about 2-4 mm is provided between the recording paper 170 and the absorbing member 260 . In addition, an interval of about 1 mm is maintained between the surface of the nozzle plate 166 and the surface of the recording paper 170 .

Furthermore, because the material of the absorbent element 260 is chosen taking into account the rate of absorption on the surface, the absorbent capacity of said material is limited. As a result, the larger waste liquid absorbing element 262 is arranged on the underside of the pressure plate 150 and the absorbing element 262 is partially in contact with the absorbing element 260 . In the waste liquid absorbing member 262, absorbing capacity is important, and therefore a material having a large absorbing capacity by capillary phenomenon is selected. Thus, the waste fluid absorbing member 262 is capable of absorbing a large amount of ink from the absorbing member 260 .

Also, the absorbing member 260 directly receives ink that is not attached to the recording paper 170 when it is discharged from the nozzle plate 166 . At this time, when the absorbing speed of the absorbing member 260 is low, a so-called "milk crown phenomenon" occurs due to the impact by which the ink collides with the surface of the absorbing member 260 . Tiny inks appear around the periphery of the "milk crown" and the inks cause the generation of aerosols. Therefore, as the absorption element 260, a material with a high absorption speed, ie a material with a high void ratio, is selected.

Moreover, in FIG. 2 , the absorbing element 260 is partially communicated with the waste liquid absorbing element 262 arranged under the platen 150 , and this structure is not shown in FIG. 2 . For this reason, since the ink absorbed by the absorbing member 260 is subsequently absorbed by the waste liquid absorbing member 262 having a higher absorbing capacity, the absorbing capacity of the absorbing member 260 lasts for a long time.

On the other hand, a conveyance drive roller 282 and a conveyance driven roller 284 are arranged behind the platen 150 to form a conveyance portion 280 . The conveyance driving roller 282 is rotationally driven by a conveyance motor 286 disposed in the rear of the frame 210 . Also, the conveyance driven roller 284 presses the recording paper 170 against the conveyance drive roller 282 . Accordingly, the conveyance driven roller 284 rotates with the rotation of the conveyance drive roller 282 , and the recording paper 170 is sent onto the platen 150 . Since the ink is discharged from the carriage 160 onto the platen 150 as described above, an image can be recorded on the recording paper 170 by the ink.

Also, the discharge driving roller 292 and the discharge driven roller 294 are arranged in front of the platen 150 to form the discharge part 290 . The discharge drive roller 292 is driven by energy distributed from the conveyance motor 286 . Also, the discharge driven roller 294 presses the recording paper 170 passing through the platen 150 against the discharge driving roller 292 . Accordingly, the discharge driven roller 294 rotates according to the rotation of the discharge driving roller 292 , and the recording paper 170 is sent outside from the platen 150 .

Also, in the internal mechanism 20 , the cover member 270 is arranged on a lateral side of the pressure plate 150 close to the side portion 212 . The cover member 270 is capable of moving up and down and thereby lifts and seals the underside of the nozzle plate 166 when the carrier 160 is stopped in its original position near the side portion 212 . Also, the inside of the cover member 270 is connected to a pump unit 272 . The pump unit 272 can absorb ink attached to the surface of the nozzle plate 166 . The ink absorbed by the pump unit 272 is absorbed into the waste liquid absorbing member 262 through a tube not shown.

Furthermore, a wiping device 274 is arranged between the pressure plate 150 and the cover element 270 . The wiping device 274 wipes the lower portion of the nozzle plate 166 to clean the lower portion of the nozzle plate 166 when the covered member 270 passes over the wiping device 274 from the carrier 160 released from the seal.

3 is a cross-sectional view typically showing the structure of an aerosol (or aerosol) generation prevention mechanism 31 formed in the above-described inkjet type recording apparatus 10 . As shown in this figure, the platen 150 includes a rib portion 154 protruding upward, and positions the recording paper 170 up and down by supporting the rib portion from the lower portion to the upper end. Also, a rib electrode 156 made of metal is installed on the upper end of the rib portion 154 . The rib electrode 156 is electrically connected to the positive electrode of the potential difference generating device 330 through the short protection resistor 320 while contacting the lower surface of the recording paper 170 . Therefore, when the potential difference generating device 330 operates, the recording paper 170 has the same potential as that of the positive electrode of the potential difference generating device 330 .

On the other hand, the nozzle plate 166 is connected to the negative electrode of the potential difference generating device 330 . Accordingly, a potential difference according to the potential difference generated by the potential difference generating device 330 is generated between the recording paper 170 and the nozzle plate 166, and an electric field E according to the potential difference is formed between the two. In addition, the potential difference generating means 330 is a constant voltage generating circuit, and when the potential difference between the nozzle plate 166 and the rib electrode 156 is changed by some reason, the potential difference generating means 330 adjusts the output so that the potential difference becomes the original value . Thus, the rib electrodes 156 form potential control electrodes for the recording paper 170 .

In the above-mentioned aerosol generation prevention mechanism 31, the rib electrode 156 can be formed of a metal having high wear resistance and high conductivity, such as stainless steel, iron plated with nickel, duralumin, metal including chromium or molybdenum. Iron, tungsten, titanium, alloys including titanium. Also, the rib electrode 156 can be integrally formed with the press plate 150 by embedding, attaching, and two-body molding using a material such as carbon, metal, or conductive polymer. Also, the rib electrode 156 can be formed by locally depositing an amorphous semiconductor or metal such as selenium and silicon on the rib portion 154 .

FIG. 4 is a schematic diagram for explaining the operation of the above aerosol generation preventing mechanism 31 . As shown in this figure, a plurality of holes 168 for discharging ink are formed in the nozzle plate 166 . Also, as indicated by arrow X in this figure, the nozzle plate 166 moves from right to left in this figure as the carriage 160 moves.

Meanwhile, the ink propelled from the hole 168 of the nozzle plate 166 forms an ink column 340 hanging down from the nozzle plate 166 at a moment immediately before the ink becomes an ink drop 342 . At this time, charges are concentrated by the so-called lightning rod effect between the front end A of the ink column 340 and the area B adjacent to the ink column 340 on the underside of the nozzle plate 166 .

That is, the above lightning rod effect means that the charging of ink droplets 342 is facilitated by region B on the surface of nozzle plate 166, which is surrounded by a vertex with ink at the top that includes the range of apex angles from 50° to 60°. The front end A (bottom end in this figure) of the column 340 is tapered. Through this lightning rod effect, the ink drop 342 has a charge q greater than the charge corresponding to the horizontal cross-sectional area of the ink column 340 and equal to the charge of the nozzle plate 166 .

On the other hand, in the aerosol generation prevention mechanism 31 , the electric field E is formed between the nozzle plate 166 and the rib electrode 156 and the recording paper 170 . As described above, since the ink droplet 342 is charged with the charge q, the ink droplet 342 acquires kinetic energy from the electric field E by the Coulomb force F(qE), and thus moves on the lower side without deceleration to finally reach the recording paper 170 . Thus, in the electric field E, since the ink droplet 344 must reach the recording paper 170, the generation of aerosols is prevented.

In addition, in the inkjet type recording apparatus 10 shown in FIGS. The order of magnitude of m. Also, when a potential difference is formed using the nozzle plate 166 as an electrode to form such an electric field, charges accumulated in liquid droplets discharged from the nozzle plate 166 are about 4×10 ⁻¹⁴ Q.

On the other hand, when the recording paper 170 is ordinary premium paper or paper made by coating porous silica on premium paper, the volume resistivity is about 10 ⁷ -10 ¹³ Ωcm. When ink having electrical conductivity passes through such recording paper 170, the volume resistivity deteriorates to 10 ⁵ -10 ⁷ Ωcm. Also, the surface resistivity of the recording paper 170 to which the ink adheres becomes approximately 10 ³ -10 ⁷ Ω/square.

Therefore, when the rib electrode 156 formed of a metal having a sufficiently high electrical conductivity contacts the recording paper 170 to be connected to the potential difference generating device 330, the potential of the recording paper 170 passes through the recording paper 170 itself and on the recording paper 170. The way of the ink can be controlled to be the same as the output voltage from the potential difference generating device 330 . Furthermore, since the electric charge in the ink drop 342 is discharged through the recording paper 170 and the ink 344 that has adhered to the recording paper 170 when the ink drop 342 is deposited (or landed) on the recording paper 170, the potential on the recording paper 170 no change.

Also, in the above embodiments, the rib electrode 156 is connected to the positive side of the potential difference generating device 330 and the nozzle plate 166 is connected to the negative side of the potential difference generating device 330 . However, although all electrodes are connected in reverse, a similar function is achieved. Furthermore, by setting the potential at one end of the potential difference generator 330 to the ground potential, wiring within the aerosol generation prevention mechanism 31 can be simplified.

FIG. 5 is a sectional view typically showing an aerosol generation preventing mechanism 32 according to another embodiment. In addition, in FIG. 5 , the same reference numerals denote the same components as in other figures, and descriptions thereof are omitted.

As shown in this figure, the aerosol generation prevention mechanism 32 according to this embodiment has a characteristic characteristic of the shape of the rib electrode 156 . That is, the rib electrode 156 passes through the rib portion 154 of the press plate 150 up and down to expose the lower end under the press plate 150 . Therefore, wiring from the rib electrode 156 and the potential difference generating device 330 can be connected at the lower portion of the pressing plate 150 .

According to this structure, since the wiring is not shown to the user, even if the functions of the rib electrode 156 and the aerosol generation preventing mechanism 32 are equal to the functions of the aerosol generation preventing mechanism 31 shown in FIG. Sex is also high.

FIG. 6 is a cross-sectional view typically showing the structure of an aerosol generation prevention mechanism 33 according to a further alternative embodiment. In addition, in FIG. 6 , the same reference numerals denote the same components as in other figures, and descriptions thereof are omitted.

As shown in this figure, the aerosol generation prevention mechanism 33 according to this embodiment has a characteristic characteristic of the shape of the rib electrode 156 . That is, the rib electrodes 156 are formed of the electrically conductive layer 157 formed on the entire surface of the press plate 150 . Instead of being coated on or vapor deposited onto the press plate 150 , such an electrically conductive layer 157 can be formed in a two-piece form with the press plate 150 . According to this structure, although the functions of the electrically conductive layer 157 of the potential control electrode and the aerosol generation prevention mechanism 33 are equal to those of the aerosol generation prevention mechanism 31 shown in FIG. The contact area widens to a maximum value, so the recording paper 170 and the rib electrode 156 stably have the same electric potential (potential). Therefore, the operation of the aerosol generation preventing mechanism 33 is also stable.

FIG. 7 is a cross-sectional view typically showing the structure of an aerosol generation prevention mechanism 34 according to a further alternative embodiment. In addition, in FIG. 7 , the same reference numerals denote the same components as those in other figures, and descriptions thereof are omitted.

In the embodiment shown in this figure, a plurality of conductive brushes 350 are arranged closest to the platen 150 as means for obtaining electrical connection with the recording paper 170 . Each conductive brush 350 is formed of an element having conductivity and elasticity, and one end thereof is electrically connected to the potential difference generating device 330 . Also, the other end of the conductive brush 350 contacts the recording paper 170 at a plurality of points. That is, the conductive brushes 350 are arranged on the surface and the back of the recording paper 170 immediately before the platen 150 in the transport direction of the recording paper 170 , and contact the front and back of the recording paper 170 , respectively. Also, the conductive brush 350 is arranged on the back side of the recording paper 170 immediately behind the platen 150 and contacts the back side of the recording paper 170 .

This configuration should introduce a dedicated element called conductive brush 350 . However, since the conductive brush 350 is a dedicated part for obtaining electrical connection, the arrangement can be freely selected. Therefore, the conductive brush 350 can be arranged closest to the platen 150, the nozzle plate 166, etc. related to aerosol collection, and thus the potential of the recording paper 170 can be effectively controlled. In addition, the conductive brush 350 can be formed of resin fibers containing carbon or metal powder, instead of a metal wire such as stainless steel.

FIG. 8 is a sectional view typically showing the structure of an aerosol generation prevention mechanism 531 according to a further additional embodiment. As shown in this figure, the platen 150 includes a rib portion 154 protruding upward, and supports the recording paper 170 from the lower portion at the upper end to position the recording paper 170 up and down. Here, in order to attach the ink discharged from the recording head 164 to the recording paper 170 , it is necessary to convey the recording paper 170 from the outside to supply it to the platen 150 . Also, the recording paper 170 to which the ink adheres on the platen 150 is sent from the top of the platen 150 to the outside to be discharged. Conveyance and discharge of the recording paper 170 are performed by a conveyance section 280 and a discharge section 290 each including a pair of rollers.

The conveying section 280 includes a conveying driving roller 282 that contacts the underside of the recording paper 170 and a conveying driven roller 284 that contacts the upper surface of the recording paper 170 to press the recording paper 170 against the surface of the recording paper 170. On the conveying driving roller 282. Here, the transport drive roller 282 is rotationally driven by a transport motor 286 . On the other hand, the conveyance driven roller 284 has no driving force, and rotates with the rotation of the conveyance drive roller 282 while pressing the recording paper 170 against the conveyance drive roller 282 . These conveyance driving rollers 282 and conveyance driven rollers 284 continuously contact the recording paper 170 from the front end to the rear end of the recording paper 170 during conveyance of the paper. Therefore, the conveying driving roller 282 is formed of a conductive material and is connected to the potential difference generating device 330 at the same time, so that the potential of the recording paper 170 can be controlled by the conveying part 280 .

The discharge portion 290 includes a discharge drive roller 292 that contacts the underside of the recording paper 170 and a discharge driven roller 294 that contacts the upper surface of the recording paper 170 to press it against the discharge drive roller 294 . Roll 292 on. Here, the discharge drive roller 292 is rotationally driven by the conveyance motor 286 through a conveyance mechanism not shown. On the other hand, the discharge driven roller 294 has no driving force, and rotates with the rotation of the discharge drive roller 292 while pressing the recording paper 170 against the discharge drive roller 292 . These discharge driving rollers 292 and discharge driven rollers 294 continuously contact the recording paper 170 from the front end to the rear end of the recording paper 170 during conveyance of the paper. Therefore, the discharge driving roller 292 is formed of a conductive material and connected to the potential difference generating device 330 so that the potential of the recording paper 170 can be controlled through the discharge portion 290 .

Also, two of the conveying drive roller 282 and the discharge driven roller 294 are formed of a conductive material and are electrically connected to the potential difference generating device 330, so that the potential of the recording paper 170 varies from when the front end of the recording paper 170 reaches the platen 150 to when the front end of the recording paper 170 reaches the platen 150. As the rear end passes through the platen 150, it can be continuously controlled. In this embodiment, the conveyance driving roller 282 and the discharge driving roller 292 are connected together to the positive electrode of the potential difference generating device 330 through the short-circuit protection resistor 320 . On the other hand, the nozzle plate 166 is connected to the negative electrode of the potential difference generating device 330 . Therefore, in the inkjet type recording apparatus 10 , an electric field E is formed between the nozzle plate 166 and the recording paper 170 .

In addition, the material of these delivery drive rollers 282 and discharge drive rollers 292 can include a metal material having rigidity and electrical conductivity, such as iron, iron plated with nickel, stainless steel. Also, in order to prevent the conveyance driving roller 282 from slipping on the recording paper 170, preferably, alumina particles are attached to the surface of the conveyance driving roller 282 to increase the frictional force of the surface. Also, instead of attaching alumina particles to the surface, the surface could be coated with a conductive rubber.

FIG. 9 is a schematic diagram for explaining the operation of the aerosol generation preventing mechanism 531 . As shown in this figure, a plurality of holes 168 for discharging ink are formed in the nozzle plate 166 . Also, as indicated by arrow X in the figure, the nozzle plate 166 moves from right to left in the figure as the carriage 160 moves.

When the recording paper 170 is directly below the nozzle plate 166 , ink droplets 342 are discharged from the holes 168 of the nozzle plate 166 toward the recording paper 170 . The kinetic energy given to the ink droplet 342 is quickly lost due to air viscous resistance after the ink droplet 342 is discharged from the hole 168 , and a part of the ink droplet 342 completely loses the kinetic energy long before reaching the recording paper 170 . Also, because the mass of the ink droplet 342 is extremely small, and thus the falling speed of the ink droplet 342 is extremely small. In this way, the ink droplets 342 floating below the nozzle plate 166 become aerosols.

Meanwhile, the ink propelled from the hole 168 of the nozzle plate 166 becomes the ink column 340 hanging down from the nozzle plate 166 at the moment immediately before the ink is the ink droplet 342 . At this time, charges are collected by the so-called lightning rod effect between the front end A of the ink column 340 and the area B adjacent to the ink column 340 on the lower face of the nozzle plate 166 .

That is, the lightning rod effect means that the charging of the ink droplets 342 is facilitated by the area B on the surface of the nozzle plate 166, which is surrounded by an area with an ink on top that includes the range of apex angles from 50° to 60°. The front end A (bottom end in this figure) of the column 340 is tapered. Through this lightning rod effect, the ink drop 342 has a charge q greater than the charge corresponding to the horizontal cross-sectional area of the ink column 340 and equal to the charge of the nozzle plate 166 .

On the other hand, in the aerosol generation prevention mechanism 531 , the electric field E is formed between the nozzle plate 166 and the recording paper 170 . As described above, since the ink droplet 342 is charged with a charge q equal to the charge of the nozzle plate 166, the ink droplet 342 obtains kinetic energy from the electric field E through the Coulomb force F(qE), and thus moves on the underside without deceleration to finally reach Recording paper 170. Thus, since the ink droplet 344 in the electric field E must reach the recording paper 170, the generation of aerosols is prevented.

In addition, in the inkjet type recording apparatus 10 shown in FIGS. The order of magnitude of m. Also, when a potential difference is formed using the nozzle plate 166 as an electrode to form such an electric field, charges accumulated in liquid droplets discharged from the nozzle plate 166 are about 4×10 ⁻¹⁴ Q.

On the other hand, when the recording paper 170 is ordinary premium paper or paper made by coating porous silica on premium paper, the volume resistivity is about 10 ⁷ -10 ¹³ Ωcm. When ink having electrical conductivity passes through such recording paper 170, the volume resistivity deteriorates to 10 ⁵ -10 ⁷ Ωcm. Also, the surface resistivity of the recording paper 170 to which the ink adheres becomes approximately 10 ³ -10 ⁷ Ω/square.

Therefore, when the conveying driving roller 282 and the discharging driving roller 292 formed of a metal having a sufficiently high electrical conductivity contact the recording paper 170 connected to the potential difference generating device 330, to pass through the recording paper 170 itself and the recording paper 170 The potential of the recording paper 170 can be controlled to be the same as the output voltage from the potential difference generating device 330 by means of ink on the ink. Furthermore, since the electric charge in the ink drop 342 is discharged through the recording paper 170 and the ink 344 that has adhered to the recording paper 170 when the ink drop 342 is deposited (or landed) on the recording paper 170, the potential on the recording paper 170 no change.

Also, in the above embodiments, the recording paper 170 side is connected to the positive side of the potential difference generating device 330 and the nozzle plate 166 is connected to the negative side of the potential difference generating device 330 . However, although all electrodes are connected in reverse, a similar function is achieved. Furthermore, by setting the potential at one end of the potential difference generator 330 to the ground potential, wiring within the aerosol generation prevention mechanism 31 can be simplified.

FIG. 10 is a cross-sectional view typically showing the structure of an aerosol generation prevention mechanism 532 according to a further additional embodiment. In addition, in FIG. 10 , the same reference numerals denote the same components as in other figures, and descriptions thereof are omitted.

As shown in this figure, in this embodiment, in each of the conveyance section 280 and the discharge section 290 , the conveyance driven roller 284 and the discharge driven roller 294 are electrically connected to a potential difference generating device 330 . Functions obtained in this way are similar to those of the configuration shown in FIG. 8 . However, this embodiment has the following advantages. That is, the conveyance driving roller 282 and the discharge driving roller 292 are mechanically connected with a rotation transmission mechanism such as a gear set for rotation driving. Thus, they can be electrically connected to the potential difference generating means 330 by using mechanical contacts in the transmission mechanism. However, in order to achieve this, the rotation transmission mechanism should be formed of a conductive material. However, in many cases, such a rotation transmission mechanism is formed of gears formed of a resin material. When such a resin material is changed to a metal material, the change causes an increase in manufacturing cost and an increase in operating noise.

In this regard, since the conveyance driven roller 284 and the discharge driven roller 294 are only supported so as to be able to be rotated, when these driven rollers are formed of a conductive material and the shaft supporting means is electrically connected to the potential difference generating means 330, the potential The differential control device can be formed simply. In addition, the material of the conveyance driven roller 284 and the discharge driven roller 294 can include iron, iron plated with nickel, a metal having electrical conductivity such as stainless steel, or a resin material containing carbon or metal powder and having electrical conductivity.

FIG. 11 is a cross-sectional view typically showing the structure of an aerosol generation preventing mechanism 533 according to a further additional embodiment. In addition, in FIG. 11 , the same reference numerals denote the same components as in other figures, and descriptions thereof are omitted.

As shown in this figure, in this embodiment, in each of the conveyance section 280 and the discharge section 290, one of the conveyance drive roller 282, conveyance driven roller 284, discharge drive roller 292, discharge follower roller 294 All the rollers are formed of a conductive material and are electrically connected to the potential difference generating device 330 . The functions obtained in this way are similar to those of the configurations shown in FIGS. 8 and 10 . However, this embodiment has the following advantages. That is, although each roller is in contact with the recording paper 170 , when the recording paper 170 is actually conveyed or discharged, each roller microscopically repeats contact and separation. For this reason, when attention is focused on a single roller, the roller is not stably attached to the recording paper 170 . However, since any one of the rollers contacts the recording paper 170 as a whole by increasing the number of rollers in contact with the recording paper 170, the potential of the recording paper 170 can be stabilized.

As described above in detail, the inkjet type recording apparatus 10 can actively collect liquid droplets to prevent generation of aerosols by forming an electric field between the nozzle plate 166 and the recording paper 170 . Also, since the recording paper 170 can be connected to the potential difference generating device 330 through the potential control electrode so as to constantly maintain the potential of the recording paper 170, it is not necessary to perform complicated control such as switching the applied voltage. Therefore, with a simple structure, a liquid ejection device that does not generate aerosols can be realized. Also, by providing the device as a configuration of a field generating unit, functions similar to those of existing liquid ejection devices can be realized.

In addition, in the above-described embodiments, a specific structure has been described by using the inkjet type recording apparatus 10 as an example. However, the liquid ejection device can be implemented as a color material ejection system in manufacturing a color filter for a liquid crystal display, an electrode forming device in manufacturing an organic EL display, an FED (Flat Emission Display), etc., in a biochip A sampling ejection head used in manufacture, a sampling ejection head as a precision pipette, an apparatus for drawing pictures and characters on artificial nails, etc., and further, the liquid ejection apparatus is not limited to them.

Although the present invention has been described with exemplary embodiments, it should be understood that many changes and substitutions can be made by those skilled in the art without departing from the spirit and scope of the present invention. Embodiments with such modifications are also within the scope of protection of the invention as is evident from the definition of the claims.

Claims (19)

1. liquid injection device, comprise jet head liquid and pressing plate, described jet head liquid has nozzle plate and the hole of liquid from nozzle plate is moved back and forth above recording materials towards the recording materials injection simultaneously, recording materials are positioned at the position towards nozzle plate on the injected direction of liquid, described liquid injection device comprises described pressing plate from the back support recording materials of recording materials:

First electrode, described first electrode is arranged on the pressing plate side between jet head liquid and pressing plate;

Second electrode, described second electrode is arranged on the jet head liquid side between jet head liquid and pressing plate; With

Potential difference produces part, and the end that described potential difference produces part is connected on first electrode, and the other end is connected on second electrode, and described potential difference produces part produce potential difference between second electrode and first electrode,

Thereby wherein said potential difference produces to adjust to export when the potential difference of part between described second electrode and described first electrode is changed and makes described potential difference become original value, and remains on the potential difference between described second electrode and described first electrode consistently.

2. liquid injection device according to claim 1, wherein

Described second electrode is the nozzle plate of conduction;

Described first electrode is electrically connected to the recording materials that are supported on the pressing plate; And

Described liquid injection device produces the liquid that electric field sprays towards recording materials from the hole of nozzle plate with electric attraction between the recording materials on nozzle plate and the pressing plate.

3. liquid injection device according to claim 2, wherein said first electrode is installed on the described pressing plate, and is electrically connected on the recording materials that are supported on the pressing plate.

4. liquid injection device according to claim 3, wherein said first electrode comprises conducting element, described conducting element be installed in the pressing plate, on the part near the back side of recording materials.

5. liquid injection device according to claim 3, wherein said first electrode comprises conducting element, described conducting element is installed on the injected direction of liquid by described pressing plate, and an end of first electrode contacts with described recording materials, and the other end is electrically connected to described potential difference generation part.

6. liquid injection device according to claim 3, wherein said first electrode comprises conducting element, and described conducting element was contacting with described recording materials with lucky at least one side after pressing plate before described pressing plate on the carrying path of recording materials just.

7. liquid injection device according to claim 2, wherein

Described liquid injection device further comprises:

Transport portion, described transport portion comprises the feed drive roller that is driven in rotation, with the conveying driven voller, described conveying driven voller rotates with the rotation of feed drive roller and simultaneously described recording materials is pressed on the feed drive roller, and described transport portion sends to recording materials on the described pressing plate; With

Discharge section, described discharge section comprises the discharge driven roller that is driven in rotation and discharges driven voller that described discharge driven voller rotates with the rotation of discharging driven roller and simultaneously described recording materials is pressed in discharges on the driven roller, and described discharge section sends recording materials from the top of described pressing plate

In feed drive roller, conveying driven voller, discharge driven roller and the discharge driven voller at least one is the conductive rollers that is formed by conductive material; And

Described conductive rollers is electrically connected on the recording materials as first electrode.

8. liquid injection device according to claim 7, wherein said feed drive roller and discharge driven roller are conductive rollers.

9. liquid injection device according to claim 7, wherein said conveying driven voller and discharge driven voller are conductive rollers.

10. liquid injection device according to claim 7, wherein said feed drive roller, conveying driven voller, all rollers of discharging in driven roller and the discharge driven voller are conductive rollers.

11. electric field generating unit that is installed on the liquid injection device, described liquid injection device comprises jet head liquid and pressing plate, described jet head liquid has nozzle plate and the hole of liquid from nozzle plate is moved back and forth above recording materials towards the recording materials injection simultaneously, recording materials are positioned at the position towards nozzle plate on the injected direction of liquid, described electric field generating unit comprises described pressing plate from the back support recording materials of recording materials:

First electrode, described first electrode is arranged on the pressing plate side between jet head liquid and pressing plate;

Second electrode, described second electrode is arranged on the jet head liquid side between jet head liquid and pressing plate; With

Potential difference produces part, and the end that described potential difference produces part is connected on first electrode, and the other end is connected on second electrode, and described potential difference produces part produce potential difference between second electrode and first electrode,

Thereby wherein said potential difference produces to adjust to export when the potential difference of part between described second electrode and described first electrode is changed and makes described potential difference become original value, and remains on the potential difference between described second electrode and described first electrode consistently.

12. electric field generating unit according to claim 11, wherein

Described second electrode is a conductive nozzle plate;

Described first electrode is electrically connected to the recording materials that are supported on the pressing plate; And

Described electric field generating unit produces the liquid that electric field sprays towards recording materials from the hole of nozzle plate with electric attraction between the recording materials on nozzle plate and the pressing plate.

13. electric field generating unit according to claim 12, wherein said first electrode is installed on the described pressing plate, and is electrically connected to the recording materials that are supported on the pressing plate.

14. electric field generating unit according to claim 12, wherein

Described liquid injection device further comprises:

Transport portion, described transport portion comprises the feed drive roller that is driven in rotation, with the conveying driven voller, described conveying driven voller rotates with the rotation of feed drive roller and simultaneously described recording materials is pressed on the feed drive roller, and described transport portion sends to recording materials on the described pressing plate; With

Discharge section, described discharge section comprises the discharge driven roller that is driven in rotation and discharges driven voller that described discharge driven voller rotates with the rotation of discharging driven roller and simultaneously described recording materials is pressed in discharges on the driven roller, and described discharge section sends recording materials from the top of described pressing plate

In feed drive roller, conveying driven voller, discharge driven roller and the discharge driven voller at least one is the conductive rollers that is formed by conductive material; And

Described conductive rollers is electrically connected on the recording materials as first electrode.

15. recording equipment, comprise record head and pressing plate, described record head has nozzle plate and ink is discharged reciprocating motion above recording materials simultaneously from the hole of nozzle plate towards recording materials, on the direction of discharging at ink recording materials are positioned at the position towards nozzle plate, described recording equipment comprises described pressing plate from the back support recording materials of recording materials:

First electrode, described first electrode is arranged on the pressing plate side between record head and pressing plate;

Second electrode, described second electrode is arranged on the record head side between record head and pressing plate; With

Potential difference produces part, and the end that described potential difference produces part is connected on first electrode, and the other end is connected on second electrode, and described potential difference produces part produce potential difference between second electrode and first electrode,

Thereby wherein said potential difference produces to adjust to export when the potential difference of part between described second electrode and described first electrode is changed and makes described potential difference become original value, and remains on the potential difference between described second electrode and described first electrode consistently.

16. recording equipment according to claim 15, wherein

Described second electrode is a conductive nozzle plate;

Described first electrode is electrically connected to the recording materials that are supported on the pressing plate; And

Described recording equipment produces the ink that electric field sprays towards recording materials from the hole of nozzle plate with electric attraction between the recording materials on nozzle plate and the pressing plate.

17. recording equipment according to claim 16, wherein said first electrode is installed on the described pressing plate, and is electrically connected to the recording materials that are supported on the pressing plate.

18. recording equipment according to claim 16, wherein

Described recording equipment further comprises:

Transport portion, described transport portion comprises the feed drive roller that is driven in rotation, with the conveying driven voller, described conveying driven voller rotates with the rotation of feed drive roller and simultaneously described recording materials is pressed on the feed drive roller, and described transport portion sends to recording materials on the described pressing plate; With

Discharge section, described discharge section comprises the discharge driven roller that is driven in rotation and discharges driven voller that described discharge driven voller rotates with the rotation of discharging driven roller and simultaneously described recording materials is pressed in discharges on the driven roller, and described discharge section sends recording materials from the top of described pressing plate

In feed drive roller, conveying driven voller, discharge driven roller and the discharge driven voller at least one is the conductive rollers that is formed by conductive material; And

Described conductive rollers is electrically connected on the recording materials as first electrode.

19. the jet head liquid of a use in liquid injection device, described jet head liquid comprises:

Head main body;

Nozzle plate, described nozzle plate are arranged in liquid by on the direction of spraying from described head main body; With

A plurality of holes, described a plurality of holes form through hole in nozzle plate, wherein

Described nozzle plate be conduction and have with external electric potential difference generating unit and divide the terminal be connected,

Thereby wherein said potential difference produces to adjust to export when the potential difference of part between second electrode and first electrode is changed and makes described potential difference become original value, and remains on the potential difference between described second electrode and described first electrode consistently.

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